Urinary SystemST120

Concorde Career College, Portland

Objectives

Define the term urinary Describe the functions of the urinary system List and identify the structures of the urinary

system and describe the function of each

Objectives

Describe the process of urine formation Trace the flow of urine from the time it begins

to form in the kidney until it exits the body Describe the mechanism by which the

urinary system helps to maintain homeostasis

Objectives

Describe common diseases, disorders, and conditions of the urinary system including signs and symptoms, diagnosis, and available treatment options

Demonstrate knowledge of medical terminology related to the urinary system verbally and in the written form

Urinary Defined

Pertaining to urine - the fluid and dissolved substances secreted by the kidneys.

Function of the Urinary System

Excrete water and waste products containing nitrogen and salts

Structures of the Urinary System

Kidneys (2) Ureters (2) Bladder (1) Urethra (1)

Kidneys - Location

Inferior to the diaphragm Protected by the ribs Enclosed in a fibrous capsule and protected

by a fat pad Contained within the retroperitoneal space Right is slightly lower than the left

Kidneys - General Information

Renal artery delivers oxygenated blood to the kidney Functional unit of the kidney is called the nephron Deoxygenated blood leaves the kidney via the renal vein

GU System Dissection Video

Kidney Structure

Three Regions:

1. Cortex

2. Medulla

3. Renal Pelvis

A More Detailed View

Renal capsule Cortex Medulla

Pyramids

Calyces Minor Major

Renal Pelvis Ureter

Microscopic Section of the Kidney

Note position of nephron in cortex and medulla

Nephron

Two Divisions:

1. Vascular

2. Tubular

Nephron

Vascular Division: Afferent arteriole Glomerulus Efferent arteriole Peritubular

capillaries Venule

Microscopic View of the Glomerulus

Nephron

Tubular Division: Bowman’s Capsule Proximal Convoluted Tubule Loop of Henle Distal Convoluted Tubule Juxtaglomerular Apparatus Collecting Tubule/Duct Minor Calyx Major Calyx Renal Pelvis Ureter

Physiology

Glomerular filtration

Tubular reabsorption

Tubular secretion

Concentration of urine

Kidney – Blood Supply

Renal artery Segmental arteries Interlobular arteries Arcuate arteries Intertubular arteries Afferent arterioles

Kidney-Blood Supply

Arterial flow through the kidney: Aorta Renal artery Segmental artery Interlobular artery Arcuate artery Interlobular artery Afferent arteriole Glomerular capillary

Efferent arteriole Peritubular capillary Interlobular vein Arcuate vein Interlobular vein Renal vein Inferior vena cava Right atrium

Ureters

Muscular tubes that convey urine from the kidney to the bladder by gravity and peristalsis

Approximately 10-13 inches in length

Ureters

Bladder

Temporary reservoir for urine

Layers Mucous membrane

Rugae Submucosa

Connective tissue Muscularis

Three layers Serosa/Adventitia

Trigone

Urination (Micturition)

Internal sphincter Involuntary

External sphincter Voluntary (with age)

Urethra Extends from the

bladder to the outside Meatus

Urethra

The tube extending from the bladder to the outside of the body

Urethral Meatus

The urethral meatus is the external opening of the urethra

Control of Urine Volume

Mainly controlled by the amount of water and dissolved substances that are reabsorbed

ANH: increases urine formation Secreted by the atria of the heart when BP increases

Aldosterone: decreases urine formation Secreted by the adrenal glands in response to

increased K level, decreased sodium levels, decreased blood pressure

ADH: decreases urine Secreted by the posterior pituitary gland when water

level in the body is too low

Micturition

AKA urination, voiding Passage of urine from the body As the bladder wall stretches, nerve impulses

are sent to the spinal cord and an emptying reflex is initiated

The reflex causes contraction of the bladder wall and relaxation of the internal sphincter and urine enters the urethra

Terms

Retention Suppression Incontinence Involuntarily Cystitis

Terms

Kidney Stones

Calculi are typically composed of calcium (75%)

Etiology unknown, but likely triggered by diet Lower calcium diet may decrease stone

formation Recur in 50% of patients

May become lodged and cause obstruction Hydronephritis

Kidney Stones

Nephrectomy

Cystoscopy

Visualization of bladder Urethroscopy Ureteroscopy